Problem: $ { \left[\begin{array}{rr}{4} & {1} \\ {-1} & {-1}\end{array}\right]-\left[\begin{array}{rr}{4} & {0} \\ {3} & {2}\end{array}\right] = {?} } $
To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{4}-{4} & {1}-{0} \\ {-1}-{3} & {-1}-{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {1} \\ {-4} & {-3}\end{array}\right]}$